1. Field of the Invention
This invention relates to an apparatus for automatically loading bone-in products into containers. The invention particularly relates to the loading of articles such as bone-in whole pork loins into flexible containers such as thermoplastic bags or pouches.
2. Description of the Related Art
In packaging machines, it is known to provide bag loading devices which take an empty bag and hold the bag open while a product is inserted into the bag. It is normal for the article to be inserted into the bag by a mechanically actuated pusher which reciprocates between a first, retracted position in which an article can be introduced into the space between the pusher and the bag loading table, and a second, extended position in which the pusher has advanced such an article onto the loading table and into the open bag.
As used herein, the term "bag" is intended to denote any open-ended flexible container of bag-like construction, and is not intended to limit the invention to any particular type of bag-like container. The invention is, for example, equally applicable to gusseted bags as to non-gusseted bags. The bags used with the device may for example be multi-layer bags having at least one layer to impart mechanical strength to the bag, and/or at least one layer to impart sealability by thermal welding, and/or at least one gas-impervious barrier layer.
Once the bag has been loaded in this way, the bag is conventionally advanced either by means of an extended movement of the pusher itself, or by alternative conveying means, to a subsequent sealing station. One example of such a system is shown in British Patent GB 2074972 B issued Oct. 5, 1983 to Nino Imperiale, where a pair of flat metal spreaders, located on opposite sides of a bag hold the bag open for insertion of a block shaped article into the bag. This bag loader does not support the total circumference of the bag, nor does the flat metal spreaders extend the full length of the bag. Another example of a conventional bag loader is disclosed in British Patent Specification No. 1516498 where the interior of the bag is subjected to atmospheric conditioning in the form of evacuation through a hollow pusher. Yet another example of a conventional bag loader is disclosed in U.S. Pat. No. 4,015,402 issued Apr. 5, 1977 to Domnitz et al. This reference discloses a bag loader for loading heavy block items such as blocks of cheese weighing 40 pounds or more into flexible bags utilizing a stream of air to hold the bag mouth open and spreader members of solid sheet stainless steel. The spreader members extend into the bag only far enough to prevent the cheese from contacting the bag sides at the sealing point.
Such bag loaders prepare the bag for use with a clipping, tying or heat sealing closing operation, but is not capable of protecting the flexible film bag from tearing caused by the bone ends along the full length of the bag during the loading operation.